In semiconductor devices for power conversion, wires are bonded to case electrodes by ultrasonic bonding or the like. For better wire bonding properties, the case electrodes need to be firmly secured to the case. As prior art, there is a design wherein case electrodes are formed by insertion molding (see, for example, PTL 1: Embodiment 3, FIG. 25 to FIG. 28, or PTL 2: Embodiment 1, FIG. 5).